Ecolox ECOBLU001GAL 1 Gallon Ecolox Pond And Lake Dye Blue pond and lake water colorant and aquatic plant growth inhibitor Environmentally friendly blue pond and lake dye enhances aesthetic of water with brilliant blue color Safe for fish, water fowl, livestock, wildlife, pets and humans as well as decorative aquatic surface plants, such as lily pads. Safe for swimming and irrigation. 1 gallon treats up to 1 acre 4 feet deep for up to 30 days No Toxic Heavy Metals - Made in the USA